Deep fat fryer assembly

ABSTRACT

A deep fat fryer assembly which includes a fryer well for containing heated cooking oil to be used in frying, and a filtering and recirculation subassembly connected to the well. The filtering and recirculation subassembly includes a housing having in one side thereof a vertically extending, foraminous, cylindrical filter element through which cooking oil from the well is drawn to remove the solid residual and burned materials from the fat. In another portion of the housing, a gear pump is located and is attached to the shaft of the motor located outside the housing, with the outlet of the pump communicating with the well for recirculating clean, filtered cooking oil from the housing to the well. The housing may be quickly disassembled to permit access to be had to the filter for cleaning the filter and replacing it, and also for maintaining and servicing the gear pump.

United States. Patent Cunningham 1 -Aug.-22, 1972 54] DEEP FAT FRYER ASSEMBLY FOREIGN PATENTS OR APPLICATIONS [7 Inventor: Cecil Cunningham, 1912 902,305 1/1954 Germany ..99/408 Mockingbird Lane, Altus, Okla. 7352.1 Primary Examiner-Leon G. Machlin I 22 Filed: April 14 97 Attorney-Dunlap, Laney, Hessin 8L Dougherty [21] Appl. No.: 133,784 57 ABSTRACT r A deep fat fryer assembly which includes a fryer well [52] US. Cl ..99/408, 210/D1G. 8, 210/416 f containing heated cooking oil-m be used in frying, [51] Int. Cl. ..A47J 37/12 and a filtering and recirculationv subassembly [58] Field of Search ..99/408, 403-407; nected to the welL The filtering and recirculation 210/4), 1316- 8 assembly includes a housing having in one side thereof. a vertically extending, foraminous, cylindrical filter [56] References cued element through which cooking oil from the well is UNITED STATES PATENTS drawn to remove the solid residual and burned materi- V .als from the fat. In another portion of the housing, a Martm gear pump is located'and is attached to the shaft of 2,578,129 12/ 1951 Daugherty -99/408 the motor located outside the housing, with the outlet l Schutm.. f the pump communicating the well for re'ci cu- GrudOSkl 8 lating clean filtered cookingoil from the housing to 3,483,982 12/ 1969 Nelson ..2lO/D1G. 8 the we|| The housing may be quickly disassembled to 3,477,361 11/1969 Bradshaw ..99/408 permit access to be had to the filter for cleaning the 3,447,685 6/1969 Blrcher ..99/408 X filter and replacing it and also f maintaining and 3,415,181 12/ 1968 Hart ..99/408 Servicing the gear pump 3,608,472 9/ 1971 Pelster et a1 ..99/408 3,573,861 4/1971 Lecrone ..99/408 X 8 Clains, 2 Drawing Figures DEEP FAT FRYER ASSEMBLY BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to filtering systems for use in conjunction with deep fat fryers, and more particularly, to a quickly attachable filtering and cooking oil recycling system which can be used to continuously filter and recycle cooking oil used in a deep fat fryer.

2. Brief Description of the Prior Art:

A prevalent practice in commercial eating establishments, such as restaurants and cafes, is to prepare certain foods by deep fat cooking. In this culinary technique, the foods are immersed in a heated cooking oil. Typically, chicken, potatoes, onions and fish may be cooked in this fashion. In some instances, the food to be cooked is covered with flour or dough before immersion in the cooking oil.

A problem which has been encountered with deep fat cooking is the accumulation of burned grease and food particles in the well of the cooker over extended periods of time, deleteriously affecting the flavor of the foods being cooked, and requiring periodic cleaning of the well after draining all of the cooking oil therefrom. The carbonaceous material resulting from prolonged burning of fats and oils is often difficult to remove, and the cleaning procedure results in undesirable downtime on the cooker.

A number of patents have recently been issued upon proposals for improving the deep fat cooking process by continuously filtering the cooking oil used therein. Most continuous filtration systems provide some form of foraminous or perforated filter element in association with a pump which continuously draws or pumps the cooking oil from the well of the deep fat fryer through the filter elements, and then recycles the cleaned cooking oil to the well after filtration.

Examples of systems which have recently been patented for the purpose of continuously filtering and recycling the cooking oil to a deep fat cooking apparatus are US. Pats. Nos. 3,447,685 to Bircher, 3,415,181 to Hart, 3,477,361 to Bradshaw and 3,483,982 to Nelson. Of these several patented systems, the Nelson system provides several advantages in that the filtering and pumping components of the system are located outside the deep fat fryer, and thus do not interfere with the positioning of food receptacles in the well of the fryer. The Nelson system'includes a filter device which is separately supported and spaced from a motor and pumping unit used to draw the cooking oil from the well of the fryer through the filter, and then recycle it to the well of the fryer. Several conduit connections are provided between the filter unit and the pump employed in the Nelson system, as well as between this pump and the well of the fryer.

BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention provides a compact, easily connected dual filter and pumping subassembly which can be quickly and easily attached to the well of a deep fat fryer or cooker unit, with the subassembly supported as a unit in any convenient location while occupying a minimum of space. The filtering and recycling subassembly is entirely self-contained within a housing, and direct access may be had to the pump and to the filter unit. The filter unit and the pump may be quickly and easily removed from the enclosing housing to permit maintenance, cleaning and replacement.

Broadly described, the present invention comprises a two-part housing including a bottom portion and a lid portion; means detachably retaining the lid portion on the bottom portion; a filter assembly in one portion of said housing frictionally and sealingly engaging the housing when the lid portion thereof is retained on the bottom portion; a pump positioned adjacent the bottom of said housing and spaced from said filter assembly, a motor mounted on the lid portion of said housing and drivingly connected to said pump; inlet means connected through the lid portion to said filter assembly and adapted for connection to the well of a deep fat fryer for conducting cooking fat therefrom to said filter assembly; and means for conveying clean cooking oil from the pump to the well of said deep fat fryer.

. In a preferred embodiment of the invention, the housing, filter assembly, pump and motor are con nected to, and used in combination with, a deep fat fryer, with the inlet means described connected through a drain cock in a discharge or drain conduit from the well of the fryer, and the means for conveying clean cooking oil from the pump to the fryer comprising a conduit which communicates with the well of the fryer on the opposite side thereof from the drain condui't.

An important object of the invention is to provide a deep fat fryer assembly which includes a compactly constructed oil cleaning and recycling system which can be quickly and easily attached to the well of a deep fat fryer to provide for continuous filtering and recycling of cooking oil used in the deep fat fryer.

Another object of the invention is to provide a system for filtering and recirculating cooking oil to a deep fat fryer, which system is compactly constructed and which affords rapid and easily accomplished access to the filtering and pumping elements included therein to facilitate maintenance and cleaning of these elements.

Additional objects and advantages of the invention will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a deep fat fryer assembly constructed in accordance with the present invention.

FIG. 2 is a vertical sectional view through portions of the deep fat fryer assembly shown in FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring initially to FIG. 1 of the drawings, shown therein is a conventional deep fat fryer, designated generally by the reference numeral 10. The fryer 10 includes and open topped well 12 inwhich a body 14 of cooking oil is located for the purpose of frying certain types of comestibles. In a widely used cooking technique, the type of food cooked in the fryer may, for example, be thinly sliced potatoes. The slices of the potatoes are contained in wire mesh baskets 16 which have handles 18 to permit them to be manipulated. Along the side walls inside the well 12, a plurality of tubular heating elements 20 are located for the purpose of maintaining the cooking oil in a heated state adequate for cooking purposes.

Mostdeep fat fryers, aspresently constructed, include a drain conduit 22 provided at the lower side thereof and containing a drain cock 23 which may be opened to permit the cooking oil to be drained from the well 12 of the fryer and discarded or cleaned for re-use.

Removal of the cooking oil is also necessary to permit carbonaceous sludge and burnt foods which tend to I become caked on the bottom and sides of the well to be removed periodically.

In accordance with the present invention, an oil cleaning and recycling system, designated generally by reference numeral 30, is connected by a conduit 31 to 3 well 12 and down into the cookingoil to, provide removal thereof by suction. The oil cleaning and recycling system 30 includes a two-part housing made up of a lower orbottom portion 32, and alid or cover portion 34 which is retained on'the bottom portion when the housing is assembled by means of a plurality of screw clamps 35 (see FIG. 1 r

As shown in FIG. 1 and 2, the lid portion 34 has an upwardly extending, protuberant cylindrical portion 36 which receives the upper end of a filter assembly designated generally be reference numeral 38. The filter assembly 38 includes a cylindrical foraminous or perforated outer shell or sleeve 40 which is sealed against the bottom of the lower portion 32 of the housing by means of a suitable gasket 42, and is likewise sealed against the top of the protuberant cylindrical portion 36 by meansof suitable gasket 44. It will be Y noted that the filter assembly 38 is frictionally retained paper 48 is of a diametric dimension to bear against the inside wall of the cylindrical shell 40, and performs a relatively. fine filtering action with respect to cooking oil passing Qtherethrough. There may further be in-. cluded within the filter paper 48 on the interior of the filter assembly 38, a material, such as copper tumings 49, which also strains or filters grease passed through the filter assembly. A vacuum alleviating vent pipe 50 is provided on the protuberant portion 36 over the interior of the sleeve or shell 40 and contains a screw-type valve 51. 7

Located in the opposite side of the lower portion 32 of the housing of the oil cleaning and recycling system 30 is a centrifugal pump or gear'pump 52. The gear pump 52 has an inlet (not shown) through which fat or grease may enter, and further has a discharge connected to a conduit 54 extending upwardly through the cover portion 34 and attached to the recycle conduit 24. An electric motor 56 is mounted on the cover portion 34 and has a drive shaft 60 extending through the cover portion and drivingly connected to the input shaft of the gear pump 52. A drain valve 62 is provided in the bottom wall of the lower portion 32 of the housing beneath the pump 52 to permit residual cooking oil.

to be drained from the housing during maintenance.

The oil cleaning and recycling system 30 can be quickly and easily connected to the drainconduit 22 of the deep fat dryer 1 0, With oil cleaning and recycling system 30 connected in the manner shown, the motor 56 is energizedto drive the gear pump 52. As

cooking oil is drawn into the pump by the rotating vanes contained in, and forming a portion of, this pump, hot cooking oil from the well l2'of-the fryer l0 is permitted to discharge through the discharge conduit 1 22 to the interior of the filter assembly 30 at substantially the same rate as the oil is pumped by the gear pump 52 through the recycle conduit 24. Cooking oil is drawn radially-outwardly from the interior of the foraminous sleeve 40, forming a,portion of the oil cleaning and recycling system 30, and in moving through the filter paper 48'and sleeve 40, residual bits 1 of bumtgrease, food particles and carbonare strained from the cooking oil so that the cooking oil outside of the forarninoussleeve 40, and within the lower portion 32 of the housing of the recycling system, is clean and ready for reutilization.

It will be noted that the recycle conduit 24 returns the cleaned cooking oil to the'opposite side of the well 12 from the side at which the discharge conduit 22 is located. There is thus maintained a circulation, within the body 14 of cooking oil contained within the well 12, as the oil moves from one side of this well to another. The location of the recycle conduit inlet to the well and the location of the drain conduit 22 do not interfere in any way with the operation of the fryer for cooking pur-.

poses.

An important feature of the present invention is the manner in which the oil cleaning and recycling system 30 is constructed. The two-part construction of the housing, which includes the'lower portion 32 and the cover or lid portion 34, permits quick and easy accessibility to the filter assembly 38 and to the gear, pump 52 for maintenance purposes. Thus, at such time as it may be desired to clean the filter assembly 38 and renew the filter paper 48 and the copper tumings 49 located and 44 to be replaced after the filter has been cleaned and reinserted in the housing. Maintenance of the gear pump 52 is easily carried out because of its accessibili- 1 ty, and the motor 56 is also, of course,.easily accessible and can be maintained without difficulty.

The deep fat fryer assembly of the invention can. be i used for continuously cleaning the cooking oil used therein without downtime on the fryer per se. Tests with the system have indicated that the cooking oil can be made to last from 50 to percent longer without replacement. Little or no cleaning of the well of the fryer due to the accumulation of burnt grease and food particles therein is required.

Although a preferred embodiment of the invention has been herein described and illustrated in the drawings, it will be understood that various changes and modifications can be effected in the described structure without departure from the basic principles of the invention. Changes and innovations of such type as do not entail a departure from such basic principles are therefore deemed to be circumscribed by the spirit and scope of the invention except as the same may be limited by the appended claims or reasonable equivalents thereof.

What is claimed is:

1. A deep fat fryer assembly comprising:

a well for containing cooking oil;

a two-part housing, including:

a bottom portion; and

a cover portion detachably retained on said bottom portion;

a filter sub-assembly in said housing and including:

a rigid foraminous cylinder sealed at one of its ends against said cover portion and at its other end against said bottom portion when said cover portion is retained on said bottom portion; and

a filter paper lining the foraminous cylinder;

a pump in the bottom portion of said housing and spaced horizontally from said filter sub-assembly;

a motor mounted on said cover portion outside said housing and drivingly connected to said pump;

first conduit means cormnunicating said pump with said well for conveying filtered cooking oil from the pump to the well; and

second conduit means connecting said well to the interior of said foraminous cylinder through the cover portion of said housing.

2. A deep fat fryer assembly as defined in claim 1 wherein said second conduit means includes:

a drain conduit connected to the lower side of said well on the opposite side thereof from the point of communication with said well of said first conduit means; and

a drain cock in said second conduit means for controlling the rate of flow of cooking oil from said well to the interior of said foraminous cylinder.

3. A deep fat fryer as defined in claim 2 and further characterized as including means for gravity draining cooking oil from the bottom portion of said housing.

4. A deep fat fryer as defined in claim 2 and further characterized as including:

a vacuum alleviating pipe on said cover portion over the space within said foraminous cylinder; and

valve means in said vacuum alleviating pipe.

5. A cooking oil filtering and recirculating system adapted for connection to the well of a deep fat fryer comprising:

a housing including:

a cover portion having a protuberant cylindrical portion;

a bottom portion having an open top cooperating with, and closed by, said cover portion; and

manually operably means for securing said cover portion on said bottom portion;

cylindrical filter means positioned in one side of said housing and having one end extending into the protuberant cylindrical portion of said cover portion and contactin sa'd cover rtion, d h vi a second end confacting the b a e porti n o sa i housing;

means on said cover portion for adjustably venting the space inside said cylindrical filter means to the atmosphere; v

first conduit means connectable to the well of a deep fat fryer and communicating with the space inside said cylindrical filter means for conveying cooking oil from said well to .said space;

a pump disposed in said housing adjacent the bottom of said bottom portion and horizontally spaced from said filter means;

second conduit means connected to said pump and adapted for conveying cooking oil from said pump through said housing to said deep fat fryer well; and

a motor mounted on said cover portion on the outside of said housing and drivingly connected to said pump.

6. A cooking oil filtering and recirculating system as defined in claim 5 wherein said cylindrical filter means comprises:

a foraminous, rigid cylindrical sleeve; and

a filter paper lining the internal wall of said cylindrical sleeve.

7. A cooking oil filtering and recirculation system as defined in claim 6 and further characterized to include valve means on the bottom of said bottom portion for gravity draining cooking oil from said housing.

8. A cooking oil filtering and recirculating system as defined in claim 7 and further characterized as including a drive shaft interconnecting said motor and pump and extending substantially parallel to the axis of said rigid cylindrical sleeve. 

1. A deep fat fryer assembly comprising: a well for containing cooking oil; a two-part housing, including: a bottom portion; and a cover portion detachably retained on said bottom portion; a filter sub-assembly in said housing and including: a rigid foraminous cylinder sealed at one of its ends against said cover portion and at its other end against said bottom portion when said cover portion is retained on said bottom portion; and a filter paper lining the foraminous cylinder; a pump in the bottom portion of said housing and spaced horizontally from said filter sub-assembly; a motor mounted on said cover portion outside said housing and driviNgly connected to said pump; first conduit means communicating said pump with said well for conveying filtered cooking oil from the pump to the well; and second conduit means connecting said well to the interior of said foraminous cylinder through the cover portion of said housing.
 2. A deep fat fryer assembly as defined in claim 1 wherein said second conduit means includes: a drain conduit connected to the lower side of said well on the opposite side thereof from the point of communication with said well of said first conduit means; and a drain cock in said second conduit means for controlling the rate of flow of cooking oil from said well to the interior of said foraminous cylinder.
 3. A deep fat fryer as defined in claim 2 and further characterized as including means for gravity draining cooking oil from the bottom portion of said housing.
 4. A deep fat fryer as defined in claim 2 and further characterized as including: a vacuum alleviating pipe on said cover portion over the space within said foraminous cylinder; and valve means in said vacuum alleviating pipe.
 5. A cooking oil filtering and recirculating system adapted for connection to the well of a deep fat fryer comprising: a housing including: a cover portion having a protuberant cylindrical portion; a bottom portion having an open top cooperating with, and closed by, said cover portion; and manually operable means for securing said cover portion on said bottom portion; cylindrical filter means positioned in one side of said housing and having one end extending into the protuberant cylindrical portion of said cover portion and contacting said cover portion, and having a second end contacting the base portion of said housing; means on said cover portion for adjustably venting the space inside said cylindrical filter means to the atmosphere; first conduit means connectable to the well of a deep fat fryer and communicating with the space inside said cylindrical filter means for conveying cooking oil from said well to said space; a pump disposed in said housing adjacent the bottom of said bottom portion and horizontally spaced from said filter means; second conduit means connected to said pump and adapted for conveying cooking oil from said pump through said housing to said deep fat fryer well; and a motor mounted on said cover portion on the out-side of said housing and drivingly connected to said pump.
 6. A cooking oil filtering and recirculating system as defined in claim 5 wherein said cylindrical filter means comprises: a foraminous, rigid cylindrical sleeve; and a filter paper lining the internal wall of said cylindrical sleeve.
 7. A cooking oil filtering and recirculation system as defined in claim 6 and further characterized to include valve means on the bottom of said bottom portion for gravity draining cooking oil from said housing.
 8. A cooking oil filtering and recirculating system as defined in claim 7 and further characterized as including a drive shaft interconnecting said motor and pump and extending substantially parallel to the axis of said rigid cylindrical sleeve. 